? for Suunto Computer Users

[cornfed]

Please see my previous posts on this thread... basically saying what you just said.

Sorry, in the post I quoted it sounded like you were asking.

Most of us put our trust into things we don't fully understand every day. The best I can do here (visavis the Cobra) is read the manual several times, and then post questions here about things I don't understand (which I just did).

My point is that you should probably have these questions answered before diving not after.

 

[miketsp]

What I was confused about is why more details weren't shown in the graph/profile.

Don't forget that the post-dive replay may give slightly different results because during the dive it is running in real time at a short sampling interval.
After the dive the replay is using 20secs or whatever other recording interval you chose.
So during this dive if you ascend violently for 10 seconds and then descend for 9 seconds, the computer will be indicating SLOW.
On the after dive profile it may not even register.
For the same reason on deeper dives the SDM may indicate different deco stops to those needed in real time.

 

[bottomrunner]

i dive with a suunto eon and have been doing so for the past 5 years i have put in 7 dives in one day on a regular basis what i have done is changed the settings so it thinks i am diving at altitude {eg: in the mountains} if the computer goes into deco.
i do what the computer tells me, then add an extra 5 min. deco. as a fudge factor.
i use to harvest sea urchens in nova scotia in 26 f. water for 9 hours a day.
started at 150 feet, and worked my way up to 15 feet in 4 hours.
of course i carried 3 computers and my tables as a last resort and never had any problems.
bottom line is do not break the rules and you will not have any problems.
if you have air in the tank at the end of the dive why not spend a few extra minutes at 15 feet to increase your fudge factor.

 

[vjongene]

According to my graph, it looks like I got the SLOW indicator early on in my dive, so I'm guessing that's what the CEILING notification was about. I obviously kept under the ceiling for the allotted time, as the computer didn't complain any further.

The profile you sent doesn't have anything in it to indicate why a CEILING notification should have appeared. There was a short period of "fast" ascent, but nothing major. In fact, these kinds of warnings are very commonplace with Suunto computers. I cannot scroll through the profile, but there is no way that it could have gotten you outside NDL at any time. Are you sure you got a CEILING warning on this one?

Another user's manual complaint I have is about the tissue loading. I haven't found much information about what the heck that's about. According to the Dive Manager manual, it says to read the Cobra manual and consult your Dive Shop. The only useful tidbit I gleaned is that you don't want any tissue grouping to exceed 100% - if it does you'll go into deco mode.

I have not figured exactly out how Suunto calculates the tissue loading. By the usual definition, you cannot load a tissue more than 100% at a given depth/pressure, so that >100% figures should only show up during ascent. This is clearly not the case in the Suunto algorithm. The best I can guess is that "100%" in Suunto parlance is a load that could lead to bubble formation in this particular tissue compartment during ascent. Maybe one of the deco gurus on the Board has a more scientific explanation.

 

[cornfed]

I have not figured exactly out how Suunto calculates the tissue loading. By the usual definition, you cannot load a tissue more than 100% at a given depth/pressure, so that >100% figures should only show up during ascent.

Why would you only have values greater than 100% during ascent? It's pretty damn easy to break 100% at depth.

 

[miketsp]

By the usual definition, you cannot load a tissue more than 100% at a given depth/pressure, so that >100% figures should only show up during ascent.

I have many dives where Suunto shows more than 100% before starting ascent.
One example attached.

PS. I will not get into a discussion about this particular deco stop as there were reasons for doing it like this under the circumstances.

 

[String]

*Waves at mother nature* We completed our safety stop which I was sitting at 18 feet for the entire time with no issues. I then got a very fast bounce from 18 feet to 10 feet due to surge and most likely having a bit to much air in my BC as I was completing my final ascent. Right there at 10 feet, the computer alarm is going off, please enjoy another 3 min at this depth which was a bit easier said then done with the surface conditions as they were now. However, I satisfied it in fear that some how I hit an NDL. Once we hooked it up to the computer I was able to see what happened.

A few misconceptions here. Firstly ALL the suuntos dial in an *optional* safety stop for every dive below i think its 6-7m. This is optional and is NOT part of the no decompression calculations. The manual states clearly it will not penalise you if you dont perform this stop in any way at all.

As for the fear of hitting the NDL - the computer will tell you. If it just has "STOP" highlighted and a 3 min countdown that is the optional safety stop. If it has the "ASC TIME" on then you are in mandatory deco and need to stay there. Its also worth noting the suunto by default switches out of ASC TIME deco into "STOP" 3 mins optional on every dive so the last 3 mins of every deco stop dive is the optional safety stop (which can be ignored). The display clears shows you if its optional stop time or mandatory stop.

As mentioned above, continuously violating the maximum ascent rate will cause the device to generate a mandatory safety stop (note, NOT deco stop). During this its obvious by the "CEILING" caption being lit in the top right. If you violate THIS ceiling for a specified amont of time i believe the computer will surface error mode and lock out for 24-48hrs (bt id have to check my manual).


As for the beeps, probably ascent rate warning. Ive never heard them underwater presumably because i wear a tight fitting 7mm hood.

Not to change the subject but i was taught that you NEVER go back down to comply with a missed safety stop............was i taught wrong?

Given its a *safety* stop not a decompression stop, in other words not mandatory i can see no reason to consider going back down to complete it, you'll only (theoretically) cause bubble problems.

As for missed deco stops, most agencies frown on in-water recompression saying instead the casualty is safer on the surface on O2 and going to a pot. However the jury is really out on whether the inevitable delay with this is safer than sending a diver back down immediately with escorts/safety divers to complete the stop.
On expeditions where medical treatment is a long way away they use in-water recompression as a primary means of fixing a missed stop.


-------

By the usual definition, you cannot load a tissue more than 100% at a given depth/pressure, so that >100% figures should only show up during ascent. This is clearly not the case in the Suunto algorithm.

I think Suunto use the compartment %s to decide when off gassing is needed before surfacing, ie decompression. From what i can gather when any tissue reaches 100% the computer has clicked into deco mode and leaves it when tissue %s drop below 100.

Thats just what i gather with a brief look up of 40 or so dives here.

 

[CelticRavenVA]

String,
Yes, you are correct, which I now know what the display means when these happen. Playing with the sim on it doesn't always give you the best idea. That given with with the new diver, new gear, when you first start seeing NDL Times, Ascent Rate Warnings, Fish, current, Surge, it can be hard to stay focused. I didn't think I had violated an NDL on the computer, but when in the water, and your computer tells you to stop, really not a bad idea to listen to it and I did. (Yes, a new diver that actually has read the manual on his computer about 4 times.)

Now? Yeah I know exactly what it was telling me and why.

A few misconceptions here. Firstly ALL the suuntos dial in an *optional* safety stop for every dive below i think its 6-7m. This is optional and is NOT part of the no decompression calculations. The manual states clearly it will not penalise you if you dont perform this stop in any way at all.

As for the fear of hitting the NDL - the computer will tell you. If it just has "STOP" highlighted and a 3 min countdown that is the optional safety stop. If it has the "ASC TIME" on then you are in mandatory deco and need to stay there. Its also worth noting the suunto by default switches out of ASC TIME deco into "STOP" 3 mins optional on every dive so the last 3 mins of every deco stop dive is the optional safety stop (which can be ignored). The display clears shows you if its optional stop time or mandatory stop.

As mentioned above, continuously violating the maximum ascent rate will cause the device to generate a mandatory safety stop (note, NOT deco stop). During this its obvious by the "CEILING" caption being lit in the top right. If you violate THIS ceiling for a specified amont of time i believe the computer will surface error mode and lock out for 24-48hrs (bt id have to check my manual).

 

[rcohn]

I have not figured exactly out how Suunto calculates the tissue loading. By the usual definition, you cannot load a tissue more than 100% at a given depth/pressure, so that >100% figures should only show up during ascent. This is clearly not the case in the Suunto algorithm. The best I can guess is that "100%" in Suunto parlance is a load that could lead to bubble formation in this particular tissue compartment during ascent. Maybe one of the deco gurus on the Board has a more scientific explanation.

You can easily load more than 100%. The 100% value reprsents a N2 loading of 100% of the M-value for direct surfacing for the compartment. Above 100% it is unsafe to directly surface and you move into mandatory decompression mode.

Ralph

 

[geraldp]

I have many dives where Suunto shows more than 100% before starting ascent.
One example attached.

PS. I will not get into a discussion about this particular deco stop as there were reasons for doing it like this under the circumstances.

Cool profile... I've never done a deco stop. You must have brought extra gas with you.
I'm curious about a couple of things... Since the tables show you should get 15 minutes at 33m I'm making the assumption that this wasn't your first dive of the day.

So why is Dive Manager giving you the red triangle symbol at the very beginning of the dive? Or is that the red diamond symbol? Is it telling you it wanted you to extend your surface interval?

Also, it looks like you spent another 5+ minutes at depth after hitting your deco limit, then about 18 minutes at your safety stop. Is that what the computer told you to do? Did the computer ever give you a FLOOR indicator?

Thanks,

Jerry